This invention relates to tube auger sections for sampling fluid at a given depth and an apparatus and method for coupling tube auger sections together in end-to-end relationship. The invention may be used more generally for coupling together elongated hollow tubes, elongated solid shafts, or elongated members either with or without flighting or other structure on the outer surface thereof.
One application for tube augers is drilling monitor wells. The purpose of a monitor well is to sample ground water or other fluids at a particular level to determine whether contaminants are present at that level. It is important that the interior bore of the tube auger sections be sealed except at the desired depth. If ground water or a contaminant at a higher level is permitted to seep into the tube, it will destroy the reliability of the monitoring at the desired level. The invention provides a reliable seal between sections of the tube auger.
Screens or access openings must be provided in the tube auger at the desired monitoring depth in the well. In the prior art, this was done by cutting a window in the tube and providing a screen therein to permit fluid to enter but to screen out sand and other particles. However, the cutting of an opening in the tube auger reduces the strength of the tube and sometimes results in the tube twisting or collapsing during the drilling process. Another known method was to cut horizontal, elongated slots in the tube section extending in a circumferential direction around the tube. However, such slots also weaken the tube and tend to become plugged with sand, soil or other debris, thus inhibiting the flow of the sample specimen into the inner bore of the tube.
There are many instances where the coupling of elongated members together in end-to-end relationship is desirable. For example, in the drilling of wells, it is desirable to connect a plurality of auger sections in end to end relationship as the well is being drilled. At times it may be desirable to couple elongated solid shafts or hollow tubes together in end-to-end relationship.
In all of these applications, it is desirable that the various sections of elongated members be rigidly coupled together and maintained in longitudinal alignment with one another. It is also desirable to couple these sections together so that they can be rotated in unison when torque is applied to them.
U.S. Pat. No. 4,821,818 discloses a coupling system for separate tube auger sections. The adjoining ends of the auger sections each include a collar which surrounds the end of the tube. The collar on one of the tubes is positioned rearwardly from the end of the tube so that the end of the tube protrudes beyond the collar. The collar on the other tube protrudes axially beyond the end of the tube. The axial ends of the two collars include projections and indentations which are adapted to mate together so as to hold the tubes against rotation with respect to one another. A hinged coupler is foldable to surround the two collars and hold them together so that the tube sections are held against axial movement away from one another.
Both of the collars in U.S. Pat. No. 4,821,818 are attached to the tube sections by slipping them over the ends of the tube sections and welding them in place. This weld joint is difficult and time consuming to do.
Therefore, a primary object of the present invention is the provision of an improved apparatus and method for sampling ground water or other fluid at a desired depth.
A further object of the invention is to provide a stronger and more reliable sampling auger section.
A further object of the invention is to provide a sampling auger section which is resistant to plugging.
A further object of the invention is to provide a tube auger with reliable leak proof seals between sections to prevent unwanted fluid or debris from entering the tube bore.
A further object of the invention is the provision of improved apparatus and method for coupling elongated members together in end to end relationship.
A further object of the present invention is the provision of apparatus and method which can be assembled in less time and with greater ease than the assembly shown in U.S. Pat. No. 4,821,818.
A further object of the present invention is the provision of an apparatus and method which can be used to couple various types of elongated members together, including solid shafts, hollow tubes, and elongated members with or without flightings or other structure on the exterior surface thereof.